As consumer electronic devices getting thinner and smaller these days, foldable display apparatuses have become an effective approach to reduce the volume of electronic devices. However, prolonged use of a conventional foldable display apparatus, especially repeated folding of the display apparatus, may result in wrinkles, scratches, or ruptures of the display apparatus.
For example, the conventional foldable display apparatus may be equipped with a touch panel for enabling an input function by touching a panel surface of the display apparatus. The touch panel may be coated with a transparent conductive film for sensing the touching of the panel surface. If the touch panel is wrinkled or ruptured due to repeated foldings, the transparent conductive film will be damaged, thus increasing its electrical resistance, and eventually corrupting the input function of the touch panel.
FIG. 1A is a cross-sectional view of a conventional adhesive structure 100. FIG. 1B is a cross-sectional view of the conventional adhesive structure 100 when it is folded by pressure P.
Referring to FIGS. 1A and 1B, the conventional adhesive structure 100 includes a first layer 120, a second layer 130, and an adhesive layer 140 for adhering the first layer 120 to the second layer 130. When the conventional adhesive structure 100 is folded by applying pressure P on both sides of the conventional adhesive structure 100, the central portion A of the conventional adhesive structure 100 is deformed by the pressure P. In the conventional adhesive structure 100, the adhesive layer 140 is usually formed of a single material throughout the entire layer. The pressure P causes stress that is concentrated in the deformed central portion A. The stress may result in wrinkles or cracks in the central portion A of the conventional adhesive structure 100, and may damage the conventional adhesive structure 100.